友人とアメリカ旅行に行き、知り合いの家で行われる集まりに参加します。主催者の方から何度かメールをいただいたのですがまだお返事していません。お詫びと楽しみにしていると伝えたい。

Dear XXX,

This is [your name].
Thank you for the invitation for the party you are having at your house. Thanks also for the detailed instructions, I am very excited. I look forward to seeing you and meeting many people there.

However, I am not good at speaking in English. I can read but I am poor at listening, speaking and writing in English. I hope I will be able to  communicate at the party.

Thank you again for your kindness.
See you soon.
[your name]